JPG (Best for General Web Graphics)
JPG (or JPEG) is a raster image that is often used for photographs on the web and is usually from the RGB colorspace. JPGs can be optimized, when saving them out of Photoshop, to find the perfect balance of small file size and high quality, which is perfect for eblasts and web graphics. A JPG can’t have a transparent background so they are always in the shape of a rectangle or square with a solid background.
PNG (Best for Transparent Web Graphics)
PNG is another raster image type. A PNG can have a transparent background and is generally larger and of higher quality. Therefore a PNG is ideal for logos or photo cut-outs on your website because it can have a transparent background and can appear on your webpage as a shape that overlays a colored background.
PSD (Native Photoshop File)
A PSD is the default type of file when creating something in Photoshop. PSDs can be saved as any of the raster graphics mentioned here, but when they are saved as such, are no longer editable. Therefore, we keep the PSDs in order to be able to manipulate and re-save graphics.
GIF (Best for Simple Web Graphics, Animations, and Small File Size)
A GIF is another raster image type. A GIF is formed from up to 256 colors from the RGB colorspace. The fewer the colors and shades contained in the image, the smaller the file size. So, a GIF is ideal for images that use just a few solid colors and don’t have gradients or natural shades. You wouldn’t want to use a GIF for a photograph, for example, but its ideal for a line drawing. A GIF can also be used for animations.
TIF (Best for High-Resolution Print)
A TIF (or TIFF) is a large raster file. It is created using the CMYK color model for printing on a four-color press and is significantly larger in file size than its JPEG counterpart. TIFs don’t have to be 300 DPI but most often are, as they are made for digital printing or traditional printing press use, which requires a resolution of at least 300 DPI.
INDD (Native InDesign Document)
An INDD if the default type of file when creating a document in InDesign. InDesign is similar to Word, but has many more capabilities, and is generally used to create magazines, books, and other similar items.*
EPS (Best for Logos, Large Graphics)
An EPS file is a vector file of a graphic, text or illustration. Because it is vector it can easily be resized to any size without loss in quality and can be edited in virtually any design program.
AI (Best for Logos, Large Graphics)
An AI file is a vector file created by Adobe, similar to an EPS, but that can only be created or edited with Adobe Illustrator. It is most commonly used when creating logos and illustrations for print layouts.
PDF (Industry Standard for
Viewing, Printing, Forms etc.)
PDF (Portable Document Format) is a file format that can be created from multiple programs, so, because of this PDFs aren’t universally vector or raster. It is a file type meant for universal portability and utility, and when being viewed by anyone on any platform, will appear as it was originally intended.
*Note on INDD Files INDD files create layouts using many file types along with the text (i.e. a page with text and a TIF photo placed on the page.) However, the graphic itself is not embedded in the document, but rather ‘linked’. Therefore, when transferring INDD files for another person to work on, all the linked graphics must be included.